CVE-2026-31756

MEDIUMCVSS 5.5/10EPSS 0.10%

Last modified

CVE-2026-31756 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: gadget: Fix spin_lock/unlock mismatch in dwc2_hsotg_udc_stop() dwc2_gadget_exit_clock_gating() internally calls call_gadget() macro, which expects hsotg->lock to be held since it does spin_unlock/spin_lock around the gadget driver callback invocation. However, dwc2_hsotg_udc_stop() calls dwc2_gadget_exit_clock_gating() without holding the lock. This leads to: - spin_unlock on a lock that is not held (undefined behavior) - The lock remaining held after dwc2_gadget_exit_clock_gating() returns, causing a deadlock when spin_lock_irqsave() is called later in the same function. Fix this by acquiring hsotg->lock before calling dwc2_gadget_exit_clock_gating() and releasing it afterwards, which satisfies the locking requirement of the call_gadget() macro.. EPSS estimates a 0.10% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: gadget: Fix spin_lock/unlock mismatch in dwc2_hsotg_udc_stop() dwc2_gadget_exit_clock_gating() internally calls call_gadget() macro, which expects hsotg->lock to be held since it does spin_unlock/spin_lock around the gadget driver callback invocation. However, dwc2_hsotg_udc_stop() calls dwc2_gadget_exit_clock_gating() without holding the lock. This leads to: - spin_unlock on a lock that is not held (undefined behavior) - The lock remaining held after dwc2_gadget_exit_clock_gating() returns, causing a deadlock when spin_lock_irqsave() is called later in the same function. Fix this by acquiring hsotg->lock before calling dwc2_gadget_exit_clock_gating() and releasing it afterwards, which satisfies the locking requirement of the call_gadget() macro.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.10%

0.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.15.187, < 5.15.203
LinuxLinux Kernel>= 6.1.143, < 6.1.168
LinuxLinux Kernel>= 6.6.96, < 6.6.134
LinuxLinux Kernel>= 6.12.36, < 6.12.81
LinuxLinux Kernel>= 6.15.5, < 6.18.22
LinuxLinux Kernel>= 6.19, < 6.19.12
LinuxLinux Kernel7.0Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-31756?
In the Linux kernel, the following vulnerability has been resolved: usb: dwc2: gadget: Fix spin_lock/unlock mismatch in dwc2_hsotg_udc_stop() dwc2_gadget_exit_clock_gating() internally calls call_gadget() macro, which expects hsotg->lock to be held since it does spin_unlock/spin_lock around the gadget driver callback invocation. However, dwc2_hsotg_udc_stop() calls dwc2_gadget_exit_clock_gating() without holding the lock. This leads to: - spin_unlock on a lock that is not held (undefined behavior) - The lock remaining held after dwc2_gadget_exit_clock_gating() returns, causing a deadlock when spin_lock_irqsave() is called later in the same function. Fix this by acquiring hsotg->lock before calling dwc2_gadget_exit_clock_gating() and releasing it afterwards, which satisfies the locking requirement of the call_gadget() macro.
How severe is CVE-2026-31756?
CVE-2026-31756 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.10% probability of exploitation in the next 30 days.
How do I fix CVE-2026-31756?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST